1. Field of the Invention
This invention relates generally to apparatus for processing a color video signal and, more particularly, is directed to a color video signal processing apparatus which is suitable for application to an integrally combined video camera and a video tape recording and reproducing device.
2. Description of the Prior Art
In a known video tape recorder (VTR) capable of playback or reproduction and being integrally combined with a video camera, an imager signal obtained from an imager device of the camera, such as, a charge-coupled device (CCD), in the recording mode, and a reproduced signal obtained from the head or heads of the VTR in the reproducing or playback mode are independently processed by a camera block and a VTR block. An imager signal processing circuit included in the camera block for processing an imager signal in the recording mode is provided with a delay line having a delay time of more than 1 horizontal period (1H) to process a signal with respect to a vertical direction of a carrier chrominance signal, and to control an aperture of a luminance signal. On the other hand, a reproduced signal processing circuit for processing a reproduced signal in the playback mode is provided in the VTR block and includes a delay line having a delay time of more than 1 horizontal period for cancelling crosstalk components or noise of the reproduced luminance and carrier chrominance signals and for forming a dropout compensating circuit.
Imager signal processing circuits which require a delay line as the line memory are those having a so-called complementary color checkered filter and an aperture control circuit. Reference is made to U.S. Pat. No. 4,731,674, issued Mar. 15, 1988, and having a common assignee herewith, as disclosing an arrangement in which a luminance signal and a carrier chrominance signal are added to each other, supplied through a single comb filter, and again separated into a luminance signal and a carrier chrominance signal.
In the prior art video tape recorders integrally combined with built-in cameras and having a reproducing or playback mode, as described above, the imager signal processing circuit and the reproduced signal processing circuit are provided with respective delay lines each having a delay time of more than one horizontal period, whereby the circuit arrangement of the apparatus has a relatively increased number of delay lines. As a result of the foregoing, the circuit arrangement is complicated and cannot be readily miniaturized. Furthermore, the video tape recorder with an integral or built-in video camera is inherently expensive and consumes an undesirably large amount of power.
Moreover, in the known color video signal processing apparatus for use with a video tape recorder integrally combined with a built-in video camera and capable of a playback mode, a relatively complicated circuit is required for processing a carrier chrominance signal according to the color-undersystem, that is, in which the carrier chrominance signal is frequency converted to a low band below the band of the frequency modulated luminance signal. More particularly, such color video signal processing apparatus requires a considerably increased number of memories in order to effect the analog-to-digital conversion of the chrominance signal in the form of a color subcarrier which is 3.58 or 4.43 MHz, for the NTSC or PAL system, respectively. Moreover, such signal processing cannot be applied to various features of the video tape recorder, such as, the variable tape speed playback and the like.